Railway traffic controlling apparatus



June 3o, v1931. 1,812,187

RAILWAY TRAFFIC couTRoLLNG APPARATUS bfc. ACKERLY Filed Feb. 24. 1927 `2 sheets-Sheet v1 INVETOR: l Dqf ww l ,mw

Y "Aix .lune 3o, 193.1. ,n.fG. ACKERLY l;812,187`

RAILWAY TRAFFIC coNTRoLLING APPARATUS A Filed Feb. 24, 192? 2*Sheets`sheatl 2 VD A HNVENTORI DG. Aue/Hy,

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Patented June 30, 1931 UNITED STATES PATENT OFFICE DONALD G. AGKERLY, 0F WILXINSBURG, PENNSYLVANIA, ASSIGNOB. TO THE UNION SWITCH & SIGNAL COMPANY, 0F SWISSVABE, PmNSYLVANIA., A. CORPORATION 0I' PENNSYLVANIA RAILWAY 'rmrrc coNraoLLINe A .Prm'rus Application led February 24, 1927. Serial No. 170,498.

controlling apparatus embodying my invenr tion, and will then point out the novel `features thereof in claims.

In the accompanying drawings, Fig. 1 is a diagrammatic view of one form of trackway apparatus suitable for co-o erationwith train carried apparatus embo ying my invention. Fig. 2 is a view, partly diagrammatic, of one form of train carried governing ap aratus embodying my invention, and suitab e for co-operation with the trackway apparatus shownin Fig. 1. Fig. 3 is a view showing a modified form of train carried governing lapparatus also embodying my invention; Fig. 4, is a detail sectional view of a portion of the apparatus shown in Fig. 3.l

Similar reference characters refer to slmilar parts 1n each of the several v1ews.

In Fig. 1 thereference tcharacters 1 and 1 designate the track rails pi a stretch of railway track. Means are provided for supplying these rails with current in the form o'f code 1m ulse combinations, the immediate source o such current being la transformer T, the primary winding 2" of which is constantly sup lied with alternating current from a suita le source not shown in the draw-` ings. The supply of energy from the transformer to the track Arails 1 and 1 is controlled by ak transmitter designated generally by the.

reference character K, comprising, 1n the form here shown, a rotatable shaft 4 which is driven at constant speed by means of a motor M supplied with alternating current from the secondary 3 of transformer T. Secured to the shaft 4 and rotatable therewith are a lurality of code wheels K1, K2, Ks and K. ach code wheel, is provided with a plurality of alternately disposed conducting segments 5 and insulating segments 6 of various len hs. A circuit controller G having a movab e arm 7 is arranged to co-operate with a plurality of stationary contacts 8, 9,

10 etc. Each of the contacts is connected to 'a hrushdesignated by the same reference character as the contact but with the exponent a. Each brush bearson the periphery of one of the code wheels so that by suitably positioning contact arm 7, the seconda 3 of transformer T may be connected wit -the track rails 1 and 1l through any one of the code wheels, and will then supply any one of a plurality of code im ulse combinations to these ralls. If it is esired to su ply uninterrupted alternating current 'to tl e track rails, the arm 7 is connected to the con-n tact 8.

The code wheel K1 is arranged to supply separated impulses of current, the length of each impulse being, for example, one-fourth of a second, and the interval between each two, impulses being one second. The code wheel K2 supplies a code consisting of impulses of one-half of a second duration with one second intervals between impulses. Code wheel Ka supplies impulses in roups ofy two impulses each, each impulse fourth of asecondduratlon, with one-fourth second intervals betweenthe impulses, in a.

. group, but with one second 'intervals between the groups, The code wheel K4 supplies impulses in groups of two impulses each, each impulse being of one-half second duration, with intervals 'of one-half second between impulses in a group, but with intervals of one second between the groups. These codes are given merely by way of example, since it is obvious that any suitable combinations ofv impulses may be used and that any suitable length of impulse may be chosen.

Referring now to Fig.v 2. the train carried governing'means comprises a air of cores 13 and 13" carried in advance o the forward axle of a train V (Fig. 1) and'disposed in inductive'relation to the track rails 1 and 1, respectively. The core 13isprovide with a winding 14, the core 1'3 with a winding 14, and the two windings 14 and 14 are connected in series so that the electromotive forcesinduced therein by alternatin currents flowing in opposite directions 1n the track rails at any instant, are additive. The two windings 14 and 14' may be connected eing of oneby means of suitable amplifying apparatus "15 with a relay Q.

The relay Q is quick-acting, that is, it picks up and releases substantially without time la when'energized and de-energized. This re ay has a bridging contact 30 which is closed only during transit from its open to its closed position and vice versa, and front and back contacts 31 and 32, respective- 1y. The bridging contact 30 controls the supply of energy from a battery H to a second relay B. The circuit for relay B is from battery H, through wire 39, bridging Contact 30, wire 40. winding of relay B, and wire 41 back to battery H. This circuit is closed momentarily during the transit of contact 30, so that the relay B is supplied with impulses oit current of twice the frequency of the impulses supplied to relay Q. The contacts 31 and 32 of relay Q control the energization of a selector W, which will be described hereinz after.

The relay B has a bridging Contact 33 simi.- lar to the Contact 30 of the relay Q, and two front contacts 34 and 35. r1`his relay has quick pick-up but slow-release characteristics, and is capable or holding its contacts 34 and 35 closed for onahal second following its de-energization. The bridging contact 33 controls the energization of a relay C over a set of contacts which are controlled by the selector W.

This selector W comprises a roto'r 16 of magnetizable material having a plurality of spaced teeth al, a2, etc., and preferably composed of several thin laminations. This rotor is mounted to rotate on a shaft 17 supported by any suitable means, not shown. Also mounted on the shaft i7 and rotatable with the rotor 16 is a pinion 18. A reciprocable rack 19 engages the` pinion 18 and is normally biased by gravity to a position in which it engages a stop 20, as shown in the drawing. The rack 19 carries two contacts 21 and 22, which are suitably insulated from the rack and from each other, and are arranged to co-operate with stationary contacts 23, 24C and 25.

For the purpose of turning the rotor 16 in a clockwise direction and raising the rack 19, I provide two magnets E and F. rlihe magnet E comprises a magnetizahle core 26, having two legs 26a and 26" the lower faces of which are provided with shading bands J. The core 26 carries a winding 23 which has a circuit from battery H, through wire 39, front contact 31 oit relay Q, contact 3ft of relay B, wire 42, winding 28 of magnet E, and wire 43 back' to battery. This circuit is completed only when contacts 31 and 34; of relays Q and B, respectively, are closed. The magnet F comprises a magnetizable core 27 having legs 27a and 27h, the upper faces of which are provided with shading bands J. The core 27 carries a winding 29, which has a circuit from battery l-l, through wire 39,

. back contact 32 of relay Q, contact 35 of' relay B, winding 29 of magnet F and wire 43 back to battery. This circuit is closed when relay Q is dsa-energized and contact 35 of relay B is closed.

When the parts are in the positions shown in the drawings, the faces of legs 26a and 26b of magnet E are each directly opposite a space between the teeth of rotor 16. When the magnet E is supplied with an impulse of current the magnetic iux from core 26 passes from the unshaded portion of leg 26, through rotor tooth a1, a bod of rotor 16, rotor tooth a3 and the unsha ed portion of leg 26D, back to core 26. Some flux also passes through the shaded portions of legs 26'l and 26", through rotor teeth a2 and a", but due to the vchoking e'ect of the shading bands J, the uX through the unshaded path predominates and the rotor is turned clockwise until teeth a1 and a3 register with legs 26 and 26h, respectively of core 26. AThe angle through which the rotor turns during` each energization of magnet E is equal to one-half of the whole pitch of the rotor, and is designated in the drawings as angle X. I will hereinafter refer to a rotation of rotor 16 through this angle as cone step. Movement of the rotor 16 through one step will bring the spaces between the teeth of rotor 16 opposite the legs of magnet F, so that when magnet F is supplied with an impulse of current the rotor will again be advanced one step to such a position that teeth aT and of register with legs 27 a and 27h, respectively, of core 27.

It will now be clear that for each impulse of current supplied to the relay Q the rotor 16 will be advanced two steps, the first step by magnet E to whnich current is supplied over front contact 31 of relay Q, and the second step oy magnet F to which current is supplied over back contact 32 of relay Q. It will also be clear that the rotor 16 is held in the position to which it is moved by one of the magnets E or F as long as such magnet remains energized. When the rotor 16 is advanced two steps, the rack 19 is raised far enough -for the contacts 21 and 22 to engage stationary contacts 23 and 2t, respectively,

and when the rotor is advanced four steps, the rack is raised far enough ior contacts 21 and 22 to engage contacts 2liand 25., respeo tively. These contacts are at times included in a circuit for a relay G, this relay being supplied with impulses of current only at the time that relay B releases its bridging contact 33 one-half second following the end of the last impulse of each code group.

The rela C is of the three-position polarized type, 'raving quick pick-u but slow-release characteristics, and capa le of holding its Contact closed between impulses supplied to it over bridging contact 33 of relay B when ne I this contact is released at the end of any code group. lThis hold-over period may lbe as much as two seconds in one example which I have chosen. When relay C is de-energized, it closes a neutral contact 36 and lights a lamp S supplied with current from a battery L over a circuit which is obvious from the drawings. When this relay receives an impulse of current over bridging contact 33 of relay B, with contacts 21 and 22engaging contacts 23 and 24, respectively, the left-hand contact 37 is closed and lam R is lighted. The circuit 'for relay C is then irom batter H, through wire 44, bridging contact-33 o relay B, Wire 45, contact 2224, wire 46, winding of relay C, wire 47, contact 21--23, and wire 41 back to battery. When the contacts 21 and 22 engage the stationary contacts 24 and 25, relay C is energized to close its contact 38 and light the lamp A. The circuit for relay C is then from battery H, through wire 44, bridging contact 33 of relay B, wire 45, contact 22--25, wire 47, winding of relay C, wire 46, contact 21--24 and wire 41, back to battery. It will be understood that the circuits for relay C just traced can be closed only during the transito the Contact 33 of relay B when relay B releases.

In describing the operation of the apparatus I will first assume that the movable arm 7 of circuit controller G is moved into engagement with the contact 8, so that uninterrupted alternating current is supplied to the track rails 1 and l from the secondary 3 of transformer T. Current will then be supplied continuously to the winding of relay Q, so that this relay will be continuously energized. Relay B will pick up-whenfcontact 30 of relay Q bridges, so that contact 34 of relay B will be closed. Magnet E will therefore be energized and will advance the rotor 16 one step. After one-half second, relay B will release and de-energize magnet E so that rack 19 will return to its position against the stop 20. Relay C will remain de-energized with the result that lamp S vwill be lighted and will remain lighted until the po-v sition of circuit controller arm 7 is changed. When no current is being supplied to the track rails, the parts will occupy the positions shown in the drawings and llamp S will be,

lighted.

If the movable contact arm 7 of circuit controller G engages the contact 9, code impulse combinations in the form of one-fourth second impulses separated by intervals of one second will be supplied to the track rails through code wheel K1. During each of the impulses the relay Q willreceive current from the track for one-fourth of a second and in picking up will cause relay B to be energized over the contact 30. Vhen relay B is energized, its contacts 34 and 35 are closed, and since contact 31 of relay Q is also closed, current will be supplied to the magnet E and the rotor 16 will be advanced one step to raise the rack 19. The movement of rack 19 due to the impulse received by magnet E will be insuiiicient to cause contacts 21 and 22 to engage with contacts 23 and 24. When relay Q releases, another impulse of current is supplied 'to the relay B over bridging contact 30 and relay B therefore remains energized. Rotor 16 and rack 19 are advanced another step, due to the energization of ma I net F over the back contact 32 ot relay So that contacts 21 and 22 engage contacts 23 and 24. Magnet F remainsenergized over back contact 32 of relay Q and holds'rack 19 up, so that when the relay B opens, the bridgin contact 33 momentarily completes a circult for the relay C through contacts 21--23 and 22--24. `Relay C is therefore supplied with an impulse of current of such polarity y as to cause contact 37 to close and so to licht lamp R. During the one second interval lietween impulses, rack 19 and rotor 16l will return to the position shown in the drawing, because relay B will open after one-halfsecond, and when relay Q icks up and releases with the next impulse ol) current which it receives, they contacts 21-23 and 22-24 will again be closed and relay will receive another impulse of current over the bridging contact 33 when relay B releases. Each time that relay Q receives an impulse, the rotor 16 and rack 19 are advanced to close contacts 21--23 and 22-24, and relay C receivesan `impulse each time that relay B opens. Re-

lay C holds over the interval between these impulses and lamp R remains lighted as lon as code impulses are supplied to the trac rails through code whe/el K1.

When the code wheel K is connected to the track rails by contact arm 7 and contact 11, code impulse combinations consisting of groupsk of two one-fourth 'second impulses Separated by a fourth second-interval and with one second intervals between the groups are supplied to the relay Q, and lamp A.` is lighted in the following manner. The first impulse of current supplied to relay Q closes the bridging contact 30 of this relay, picking up relay B and closing its contacts 34 and 35. Contact 31 of relay Q is also closed, so that magnet E is energized to advance the rotor 16 one step. Vhen therelay Q releases at the end of the first impulse, contact 31 opens and contact 32'closes. Rela B holds over theensuing one-fourth secon interval, therefore Contact 35 of rclayB remains closed and magnet F is energized to advance the rotor 16 another step, raising the rack 19 and bringing contacts 21`and22 into engagement with contacts 23 and 24. Relay C does not receive an impulse of current, because re lay B holds over the interval between impulses so that contact 33 of relay B does not bridge. Rack "19 is held in its advanced position during the interval, because magnet F remains energized over back contact 32 of relay Q and contact 35 of relay B, so that,

at the end of the interval when another onefourth second impulse is supplied to relay Q, rotor 16 will be advanced two more steps, one step by magnet E andA one step by magnet F, bringing contacts 21 and 22 into engagement with contacts 24 and 25, respectively. When relay B releases following the fourth impulse of current which it receives by release of relay Q, an impulse of current will be supplied to relay C over bridging contact 33 of relay B, closing the contact 38 of relay C and lighting the lamp A. The relay C holds the contact 38 closed during the interval while rack 19 returns to its bottom position and is again being advanced by the next group of impulses, and this relay receives an impulse of current each time that relay B releases following the second impulse of each group, hence lamp A remains lighted as long as code impulse combinations are supplied to the track rails by the code wheel K1.

It will be understood that if a failure of any of the circuits should occur, relay C would release, closing contact 36 and lighting the lamp S.

The apparatus shown in Fig. 2 is designed to give three indications. If a greater number of indications are desired, I may make use of the modified form of train carried apparatus shown in Fig. 3.

Referring now to Fig. 3, the main relay, which is here designated Q1, has front contacts 80 and 55, bridging contacts 70 and 94 and a back contact 59. The bridging contacts and 94 are closed momentarily during transit from open to closed position and vice versa, and contact 94 when closedy completes a circuit for a brake magnet Y which will be described hereinafter. When contact 70 is closed a circuit is completed for a relay B1, which circuit is from battery P, through wire 54, bridging contact 7 0 of relay Q1, winding of relay B1, and wires 69 and 58 back to battery P. Whenever this circuit is closed, an impulse of current is sup lied to the relay B1, and these impulses are o twice the frequency of the impulses supplied to relay Q1. The relay B1 is similar to relay B in Fig. 2, and has two front contacts 56 and 60, which are closed whenever the relay is energized, and remain closed for one-half second after the relay is deenergized. The contacts 56 and 60 are included in the control circuits for a selector Z.

The selector Z comprises a rotor 48 of magnetizable material and having a plurality of spaced teeth a1, az, etc. This rotor is secured to a shaft 481, mounted in suitable journals not shown, and is biased to the position shown in the drawings by means of a counterweight 50. The rotor 48 may be rotated in a clockwise direction by means of two magnets E1 and F1, which are similar to the magnets E and F, shown in Fig. 2, and operate in a similar manner. The magnet E1 comprises a magnetizable core 52 havin two rejecting legs provided with shading ands j), and carries a winding 521. This magnet has a circuit from battery P through wire 54, front Contact 55 of relay Q1, contact 56 of relay B1, wire 57, winding 521 of magnet E1 and wire 58 back to battery. When this circuit is closed, the magnet is energized and the rotor 48 is advanced clockwise one step, bringing two of the rotor teeth into registration with the two legs of core 52. The magnet F1 comprises a magnetizable core 53 having two ro- ]ecting legs provided with shading ban s J. The core 53 carries a winding 5311. 'Ihe circuit for magnet F1 is from battery P, through wire 54, back contact 59 of relay Q1, contact 60 of relay B1, and winding 53a of magnet F1 back to battery P. When this circuit is closed with the rotor 48 in an advanced position in which two spaces between the rotor teeth are opposite the legs of core 53, the rotor is advanced one step, so that two teeth of the rotor register with the two legs of core 53. If, for example, the parts are in the positions shown in Fig. 3, and ma et E1 is energized, the rotor will be advanced until teeth a1 and a1 register with the legs of core 52 and will be held in this position until the circuit for magnet E1 is opened. If magnet F1 is then energized, rotor 48 will be advanced another step until the teeth a and a1 register with the legs of core 53 and will remain in this position until magnet F1 is de-energized. It will, therefore, be seen that the magnets E1 and F1 are so placed with respect to rotor 48, that when these magnets are alternately energized the rotor will be advanced by successive steps.

The rotor 48 carries a contact 64 suitably insulated therefrom, and a pin 62. (See also Fig. 4.) The pin 62 and the contact 64 are arranged to co-operate with a shoulder 61 and a contact 63, respectively, on a contact disk 86. This disk is of insulating material and carries, in addition to the shoulder 61 and contact 63, a contact and a counterweight 51. The disk 86 is freely mounted on a rotatable shaft 491 and carries a pawl 871 which co-operates with a ratchet wheel 87 fixed to the shaft, thus permitting the disk to rotate in one direction independently of the shaft 49a when the disk is driven by the rotor 48. The shaft 49a also carries a rotor 49 similar to the rotor 48, and controlled by a brake magnet Y. This lmagnet comprises a core 65 of magnetizable material provided with a winding 66. The magnet Y has a circuit from battery P, through wire 92, contact 64 on rotor 48, contact 63 on disk 86, wires 96 and 89, winding 66. and wires 90, 69 and 58 back to battery. This circuit is closed only when contacts 64 and 63 on rotor 48 and disk 86 respectively,- are in engagement. Magnet Y also has a circuit from battery P through wire 54, bridging contact los 94 of relay Q1, wires 95 and 89, winding 66. of magnet Y, and wires` 90, 69 and 58back to battery, and this circuit iscompleted each time that contact 94 is closed by relay Q1 picking up or releasing. The purpose of the bridging contact 94 is to decrease tlie lenfgth of time that brake magnet Y must hold a ter the circuit of the ener izing winding 66 is opened, particularly W en the selector Z is changing from one code to another. v vv Vhen the magnet Y is energized by closing eitlier of the circuits just traced,iliux passes from one end of the core through the rotor 49 and back to the other end of the core, and holds the rotor in a lposition in which two lof the rotor teeth register with the ends of tlie core. When the rotor is locked in this in anner, the disk 86 may rotate clockwise with out turnin the shaft 491, because the pawl 87 will ri e freely over `the teeth of ratchet,

wheel 87. The magnet Y is designed to have slow-release characteristics, the core 65 being Aprovided with a short-circuited conducting sleeve 93, so that the rotor 49 is not released until substantially three-fourtlishof asecond after the circuit for winding 66 1s opened.

When the rotor 48 is ldriven clockwise it carn ries the Contact disk-86 along with it, the

pin 62 engaging shoulder 61, Vbut since the contacts 63 and 64 complete acircuit for the brake magnet Y, this ymagnet is energized and the rotor 49 and shaft 491are locked in position. y vanced andthe circuits for both magnets E1 and F1 are opened, and suiicient time Yhas elapsed for the brake magnet Y to release the rotor 49, the disk 86 will return under the v action of counterweight 51 and `lwill carry with it the shaft 491 yand the rotor49, because the pawl 87l will enga e the ratchet Wheel 87 for thisdirection o rotation. IA spring 91 is mounted between the'rotor 49 and the contactjdisk 86 and looselyl engagesy these membersl for the purpose of absorbing shocksv whichv ymight cause the disk 86 to vibrate. i l

The contactgifon disk 86 is arranged to` engage with ,any `one 10i? several stationary.

contacts 76 77 and 78 for controlling signals, here shown asslainps S1, N1, etc. c This contact is connected with one yterminal of the batter P by means of a wire 73. When the dis 86is in the normal position shown'in the drawings, the contact 75 engages vthecontact 6 thus completing a circuit or the lampS1"f This circuit is froin'loatteryy '1), through Wire 7 3, contact 7 5-76, lampS1, i

and wires 79 and 58 yback to battery. When the disk` 86 is moved to a-position in `Which contact 75 engages contact 77, either ofthe lamps N1'orR1may be lighted, depending upon which of the contacts 82 or 83 is closed.

When disk y8.6 occupies such a position that contact 75 engages contact`78, either of the lamps E1. or A1 may be lighted, depending After the rotor 48 hasfbeen ad,

upon which of the contacts 84 or 85 is closed.

The circuits for lamps N1, R1,E1 and A1 will.

be obvious from theone traced. The

contacts 82, 83, 84 and 85 are controlledby a relay D. This relay has slow-pick-up and slow-release characteristics, and is s o adjusted that it will not pick up when impulses of` `one-fourth second duration are supplied to it, but it will pick-up when impulses of onehalf second duration are supplied to it. This relay is capable of holding its contacts Vclosed for substantially one second following-its.

yde-energi'zation. Y' The circuit for this relay y is controlled by yfront contact 8O of relay Q1.,y

This circuit is frombatteryP, through wire 54, front contact of relay relay Q1 is energized. When relay Dis receiving one-fourth secondy impulses with con'- tact 7 5--7 7 closed, contact 82 will beopen and vcontact 83 closed, hence the lamp R1 will be lighted, but if one-half second impulses are bein received, the contact 82 will be closed and amp`N1 will'be lighted. The contacts 84 and 85 of this, relay control the lamps E1 7 of circuitA 'controller G engages contact 8,y

so that uninterrupted alternating current is the apparatus y Vand A1v in a similar manner when contactV` lsupplied to thetrack rails. c When the irst4 impulse of current is supplied` to relay' Q1' this relay will pick up, closiiigfthe bridging ico contactjO and supplying an impulse of curl rentto the relay B1 over a circuit froiiibat i tery P, through w1re 54, bridging contact 7 0,

of relay Q1, windin ofrelay B1, and yWires 69 and 58 f back to pick up closing its contacts 56 and 60', and v since contacts 55 of relay Q1 is also closed current will be supplied to the magnet E1- over the contactsy 55 and 56. The rotor 48 will therefore be advancedin a clockwise diey rection one step, carryin Vwith it the con-v tact disk 86 b means of pin 62 and shoulder 61. Durin t is movement thev pawl 871 will ride over t e teeth of ratchet wheel 87 because the magnet Y will be energized due to theengagement of contacts 63l and 64, and

also due to the closing of bridging contact.

94,'sov that rotor 49 and shaft 49a are held stationary.v This movement'of disk 86 will advancecontact 75 but ywill not disengage the contacts 75 and 7 6 to'de-energiz'e the lamp S1 because of the width of contact 76. HAfter ahalf second interval the relayf B1 will openl,

its contacts and magnet E1 will be de-ener-V gized, so that the rotor 48fwi11 return to itsv normal position under the action of counterweight 50 and will disengage shoulder 61 and 64.

therefore become de-energized, and after an interval of approximately three-fourths o'f a second the rotor 49 will be released, hence the disk 86, together with shaft 49l1 and rotor 49, will be returned to the position shown in the drawings by means of counterweight 51. When no current is being supplied to the track rails the lamp S1 is lighted, contacts 75 and 76 being in engagement, as shown in the drawings.

When the Contact arm 7 engages contact 9, a series of impulses of one-fourth second duration separated by intervals of one second are supplied to the track rails throu h the code wheel -K1. wWith the. parts in t e positions shown the first impulse of current supplied to relay Q1 will cause it to pick up, closing contacts and 80. When contact 70 bridges during transit, an impulse of current will pick up the relay B1 thus closing its contacts 56 and 60, so that current is supplied to the winding 521 of magnet E1' for a period of one-fourth second and rotor 48 is advanced one step, carryingdisk 86 around with it. The contacts 63 and 64 are in engagement hence the circuit for the brake magnet Y remains closed during this movement, and rotor 49 is held stationary. At the end of the one-fourth second impulse, relay Q1 drops closing its back contact 59, and since the relay B1 is slow releasing, current will be supplied to the winding 53l1 of magnet F1 over the contact 60 of relay B1, and this magnet will advance the rotor 48 another .step bringing` contact into engagement with contact 77. A circuit will therefore be com` leted for the lam y R1. This circuit is from Eattery P, throng Wire 73, Contact 75-77, contact 83 of relay D, lamp R1 and wires 79 and 58 back to battery. After relay Q1 is de-energized, the relay B1 holds over the ensuing one-half second, then releases and counterweight 50 returns the rotor 48 to its initial position. Contact 64 is carried away from contact 63 so that the circuit of magnet Y is opened but the rotor 49 is not rotated by the counterwei ht 51 on disk 86, because the magnet Y hol s over the remaining onehalf second of the one second interval before it is again ener 'zed over bridging Contact 94 when relay 1 picks up. At the end of the one second interval'rotor 48 is again advanced two steps until pin 62 and shoulder 61 engages and until contacts 63 and 64 re-engage to again complete the circuit for magnet Y. The contact disk 86 is therefore held in the position in which the contacts 75 and 77 engage, and the rotor 49 is locked in position by the magnet Y, hence the lamp R1 remains lighted. As long as code impulses are supplied to the track rails by code wheel K1, the rotor 48 is periodically advanced two steps by the magnets E1 and F1, and then K returned to its normal position under the action of counterweight 50, and each time that relay Q1 picks up or releases an impulse of current is supplied to the brake magnet Y over bridging contact 94 and current is also supplied to this magnet whenever the contacts 63 and 64 engage. Energization of the magnet Y prevents the disk 86 from returning so that the lamp R1 remains lighted as long as this code is supplied to the relay Q1.

When the arm 7 or circuit controller G engages contact 10, and code impulses are supplied to the track rails by code wheel K2, the operation of the apparatus is similar to that just described in connection with code wheel K1, except that the impulses of current supplied to the track rails are of one-half second duration so that relay D picks up, closing contact 82 and lighting lamp N1.

If circuit controller arm 7 engages contact ll, the code wheel K3 supplies current to the track rails in the form of a code consisting of groups of two one-fourth second impulses separated by one-fourth second intervals, the groups being separated by one second intervals. The first impulse of current of each group picks up relay Q1, closing its contacts 8O and 55. Contact 70 of relay Q1 bridges in transit and supplies an impulse of current to relay B1 whichv picks upn closing its contacts 56 and 60. Magnet E1 is then ener gized to advance the rotor 48 and disk 86 one step, and at' the end of the one-fourth second impulse when relay Q1 releases, the magnet F1 advances the rotor 48 and disk 86 another step. The relay B1 holds its contacts closed during the ensuing one-fourth second interval, so that magnet F1`remains energized and holds the rotor 48 in its advanced position in which contact 7 5-77 will be closed. At the beginning of the second impulse of the group when relay Q1 picks up, rotor 48 and disk 86 are again advanced one stepv by the magnet E1 and at the end of this one-fourth second impulse when relay Q1 releases, they are advanced another step by the magnet F1. It will therefore be clear that for each group of impulses the rotor 48 is advanced four steps, carryin with it the disk 86 and bringing contacts g5 and 78 into engagement. Each time that bridging contact 94 is closed and whenever the rotor 48 advances the disk 86, a circuit is completed for the brake magnet Y, so that the rotor 49 is held in fixed position.- When the conta/cts 75 and 78 engage, a circuit is completed for the lamp A1. This circuit is from battery P, through wire 7 3, contact 7 5 7 8 contact 85 of relay D, lamp A1, and wires 79 and 58 back to battery. Relay D is not energized by the onefourth second impulses of this code, hence the lamp A1 is lighted and remains lighted as long as the track rails are supplied with currentI from the code wheel if the arm 7 of circuit controller G engages contact 12 so that current is supplied the rotor in this advanced position because Supply to the track rails by code Wheel K, the relay Q1 will receive groups of impulses made of two one-half second impulses separated by intervals of one-half second, the groups being separated by one second intervals. The operation of the apparatus will be the same as when the supply of current is controlled by code wheel K3, except that the relay D will be picked up by the one-half second impulse and will close its contact 84 so that lamp E1 is lighted.

I will now assume that arm 7 of circuit c ontroller G engages contact 11 and that code 1mpulses are being supplied to the track ralls through code wheel K1, so that lamp A1 1s lighted, and that arm 7 of circuit controller G is suddenl shifted to engage the contact 9, so that co e impulses are supplied to the track rails through code Wheel K1, the change being made so that an interval of one second intervenes between the last one-fourth second impulse from code wheel K11 and the first onefourth second impulse from code wheel K1. At the end of the last impulse from code wheel K3, relay Q1 will4 release to close its back contact 59, so that magnet F1 is energized and holds the rotor 48 in its advanced position. Contact disk 86 will occupy a position in whichcontacts 75 and 7 8 engage and lamp A1 will be lighted. Magnet Y will be energized and rotor 49 will be locked in position. When relay B1 releases after one-half second magnet F1 will be deenergzed and rotor 48 will immediately be returned to its normal position by counterweight 50 and will disengage contacts 63 and 64 to out oil' the of current to brake magnet Y. Brake Y will hold the rotor 49 in its posirevent contact disk 86 from y counterweight 51. After another half second and before m et Y releases, the first one-fourth secon impulse through code wheel K1 will pick up relay Q1, again supplying current to magnet Y over bridging contact 94. Magnet E1 will advance the rotor 48 one step, and at the end of the impulse when relay VQ1 releases magnet Y will receive another impulse to continue to hold contact `78 closed. Magnet F1 will advance the rotor 48 another step'and will hold magnet tion and will beinfr rotated relay B1 will remain energized for one-half second during the first one second interval. The contact disk 86, however, occupies a position corresponding to four steps of the rotor 48, hence the impulses from code Wheel K1 will not advance the rotor 48 far enough to close contacts 63 and 64. After approximately three-fourths of a second following the release of relay Q1 at the 'end of the first. impulse through code wheel K1, magnet Y will release the rotor 49 and counterweight 5l will rotatethe disk 86, together with shaft `491 and rotor 49, backward vuntil the shoulder 61 on disk 86 engages the pin 62 on rotor shorter than said interval between 48 this' rotor nowvbeinv in its starting posi` tion, and'contacts 63 and 64 re-engage to complete a circuit vfor'the brake'magnet Y, and to lock the rotor 49. Theoperation willv now bethe same as explained in connection with the'code wheel K1 starting with the'parts in the positionsshown in the drawings.H rEach impulse .of current supplied to the vrelay Q1 from code wheel K1 will advance the rotor48 two steps, so that disk 86 will return to'su'ch' a position that `contacts'7`5 and 7 7 'are brought into engagement and a circuit is completed to light theflamp R1. AThe lamp R1vwi'll thenv remain lighted as long .ascode wheel K11 is .con` nected to the track rails. Asimilarfaction takes place in making other` changes between codes' and will be readily;- understood? {with-f,l ourt further explanation. I haveillustratedl apparatus `for giving only fiveindications,l butitisobvious thatmy apparatus tisl "*no't limited to'thisl number." l' Although I hav'ejherein'shown fand dpescribed only two forms of railway trailiciconf. trollingapparatus embodying In invention; it is understood that various cliang'es y'and modifications may be made therein-"within the scope ofthe appended claims without. departing from Vthe spirit' and scope offmy invention. I Having thus described my invention, what Iclaim isf f l. In combination, a relay Q1',means*for supplying saidrelay with ygroupsffof energy impulses of variable number of impulses in the groups, thetime interval between groups beingrelatively long and the time interval between the impulses in each group being relatively short, a momentary brid n contact operated by the armature of szlig1 rela a relay B having a release period longer than said interval between impulses of a group and y oups, a

circuit for rela B including said ridging contact, a stepy-step motor having al movable member iased to an initial position'and two windings arranged when alternately energized to move said member step-by-step away from initial position, a circuit "for one of said windings including front contacts of relays Q and B connected in series, a circuit for the other winding including a back contact of relay Q and a front contact of relay B, whereby said motor member is moved two steps away from its initial position for each im ulse in each group and returnsto its initia positionfbetween each two oups of impulses, and signalin means se ectively controlled by the relay upon its release at the end of each group of impulses and by the position assumed by the movable member at the end of theimpulse group in response to the number of impulses in the grou 2. In combmation, a relay means for 'supplying said relay with grou s of energy impulses of variable number ofp impulses in the groups, thetime intenval between groups being relatively long andthe time interval between the impulses in: each roup being relativelyl short, `a. momentary. ridging contact operated by thearmature'oflsaid re1ay,.a ref layB havinga release period longer than said interval .between impulses `of a .group and shorterthan said intervals bet-Ween' groups, a circuit :for relay Blincluding said lbridging lo contact, a step-.by-step motorV having a movrable member biased to an initial position and two"windings arranged vwhen alternately en` ergized to `move said member step-by-*step away from initial position, acircuit for one ,15 of said windings including vfront contacts'of relaysr Q land B connected in series, `a circuit or'the` other winding including ay back contact of relay Q and afront contact of relay B, whereby said'motor member is :moved two 29 'steps away from its initial position foreach impulse in each group and returns to its initial position between-each two groups of im pulses,1 a circuit controller lvariably posi- `tion'ed by said `member at the end of each ifm- `5:3 pulse group depending upon the number of impulses in the group, a relay C having a release period longer than said interval between 5 groups of impulses,v a lmomentary bridging contact operated by the armature of relayB, iuponits release and circuits for said relay C `controlled by said `circuit controller in its various positions `at the endl of the impulse olps and by said bridging Contact of reay 5 1 In testimony whereof I aix my signature.

DONALD G. ACKERLY. 

